1. Field of the Invention
The invention relates generally to ablation systems and, more particularly, to systems and methods for validating and troubleshooting the set-up of radio frequency (xe2x80x9cRFxe2x80x9d) ablation systems.
2. Description of the Related Art
A typical RF ablation system includes a power control system, one or more patient return electrodes and a catheter having a one or more electrodes for transferring ablation energy from the power control system to biological tissue. Additional components may include a cardiac electrophysiological (xe2x80x9cEPxe2x80x9d) monitoring system for recording intracardiac electrograms (xe2x80x9cECGsxe2x80x9d) through the catheter electrodes and a computer for viewing and logging ablation data.
During ablation system set-up the user manually connects each of the devices to the power control system and verifies the connections are proper. With respect to the patient return electrodes, e.g., backplates, this requires that the user connect the patient return electrode to the power control system to establish a return path for the RF current traveling through the tissue. Current market available patient return electrodes incorporate a self adhesive perimeter and conductive gel pad. The pad portion of the patient return electrode must be secured to the patient to complete the return path. During initial set up, adequate contact between the patient and the pad is verified visually by the user. After set up, the patient return electrodes are typically located under drapes thereby hiding them from visual view of the operator. At times inadequate contact between the pads and the patient may result from cable movement, perspiration, patient movement or a combination. In addition, the gel applied to the area between the pad and the patient may cause the pad to become displaced. Such post set-up conditions may go unnoticed by the user due to visual obstruction of the patient return electrodes.
With respect to the computer, the user must manually connect the computer cable, such as an RS232 cable, to the serial data port of the power control system and verify that the connection is proper. The computer typically includes some type of ablation related software that interacts with the power control system. For example, the computer may be programmed to receive ablation data, e.g., temperature, voltage, current, etc., from the power control system and log the data for future review and analysis. The computer may also display the ablation data. Even though the computer cable may be physically connected to the power control system, the communication link between the software and the power control system may not be established due to problems with computer communication parameters or the absence of the appropriate active communication software.
With respect to the cardiac EP monitoring system, commercially available systems have individual input connectors for displaying individual ECGs and physiological data on multiple channels. A typical ablation catheter, however, has a single multiple pin connector connecting to an interface breakout box with single pin connectors. The user must connect the catheter connector pins to the EP monitoring system pins in the correct pin sequence for the system to operate correctly and to properly display ECGs signal in the correct sequence. Mistakes are common and significant time is spent troubleshooting EP monitoring system connections. If EP monitoring system connections are improper or gains are not the same, there is a significant risk of an incorrect channel sequence or incorrect amplitude leading to misinterpretation of signals.
Given the number of devices within an ablation system and the external factors effecting the integrity of an ablation system, operators spend a significant amount of time verifying system set-up prior to performing ablation procedures. If set-up problems are detected, additional time is required to troubleshoot the system to locate the source of the problem.
Hence, those skilled in the art have recognized a need for an ablation system with the capability to validate ablation-system device interconnections and to troubleshooting invalid interconnections. The need for interactive troubleshooting capability to minimize procedure time and provide corrective actions has also been recognized. The invention fulfills these needs and others.
Briefly, and in general terms, the invention is directed to systems and methods for validating and troubleshooting the set-up of an ablation system.
In a first aspect, the invention relates to a method of troubleshooting an ablation system having at least one patient return electrode, a power control system adapted to output power signals, a computer, and a cardiac electrophysiological (xe2x80x9cEPxe2x80x9d) monitoring system. The patient return electrode, computer and EP monitoring system are adapted to connect to the power control system at a patient-return-electrode receptacle, a data port and an EP-monitoring-system receptacle respectively. The patient return electrode is further adapted to contact biological tissue. The method includes verifying the connection between the power control system and the patient return electrode and verifying that adequate contact exists between the patient return electrode and the biological tissue. The method further includes verifying the connections between the power control system and the computer and between the power control system and the EP monitoring system. After successful verifications, the power control system is allowed to output power signals for ablation therapy.
In a detailed aspect, the patient-return-electrode receptacle includes a switch which, in the absence of an inserted connector, is open. Verifying the connection between the power control system and the patient return electrode includes confirming that the switch or circuit is closed. In a further detailed aspect, confirming that the switch is closed includes outputting a test signal to the input of the switch and monitoring the output of the switch for the signal. A still further detailed aspect of the method includes generating an error indication when the switch is open.
In another detailed facet, the patient return electrode includes at least two electrically isolated return electrode pads. Verifying adequate contact between the patient return electrode and the biological tissue includes measuring the impedance between the return pads and comparing the impedance to an expected value. In a further detailed facet, the method includes generating an error indication when the measured impedance is greater than the expected value.
In another detailed aspect, the data port includes a switch which, in the absence of an inserted connector or completed circuit, is open and verifying the connection between the power control system and the computer includes confirming that the switch is closed. In a further detailed aspect, confirming that the switch is closed includes outputting a test signal to the input of the switch and monitoring the output of the switch for the signal. In another further detailed aspect, verifying the connection between the power control system and the computer further includes establishing communication between the power control system and the computer. In a still further detailed aspect, establishing communication between the power control system and the computer includes polling the computer and waiting for an answer and verifying the presence, initialization and correct setting of appropriate software in the computer.
In another detailed facet, the power control system has a multiple pin EP-monitoring-system receptacle and the EP monitoring system includes an EP recorder having a plurality of inputs and a display for displaying ECG signals. Verifying connection between the power control system and the EP monitoring system includes outputting a signal of a given amplitude to each of the EP-monitoring-system pins in sequence and monitoring the EP recorder display for receipt of each signal in sequence. In a further detailed aspect, each of the signals is a pulse signal having substantially the same amplitude and verifying connection between the power control system and the EP monitoring system further includes monitoring the EP recorder for consistent amplitudes among each of the received signals and calibrating the EP monitoring system in accordance with the amplitude.
In another aspect, the invention relates to an ablation system including a power control system adapted to output power signals. The power control system includes a patient-return-electrode receptacle, a data port and an EP-monitoring-system receptacle. The ablation system further includes a patient return electrode adapted to connect to the patient-return-electrode receptacle, a computer adapted to connect to the data port and an EP monitoring system adapted to connect to the EP-monitoring-system receptacle. The ablation system also includes a processor that is programmed to verify the connection between the power control system and the patient return electrode; verify that there is adequate contact between the patient return electrode and the biological tissue and verify the connection between the power control system and the computer. The processor is also programmed to verify the connection between the power control system and the EP monitoring system and after successful verifications, allow the power control system to output power signals.
These and other aspects and advantages of the invention will become apparent from the following detailed description and the accompanying drawings which illustrate by way of example the features of the invention.